radical — ODE

radical /ˈradɪkl

▸ adjective

1 (especially of change or action) relating to or affecting the fundamental nature of something; far-reaching or thorough:

a radical overhaul of the existing regulatory framework.

▪ forming an inherent or fundamental part of the nature of someone or something:

the assumption of radical differences between the mental attributes of literate and non-literate peoples.

▪ (of surgery or medical treatment) thorough and intended to be completely curative.

2 advocating or based on thorough or complete political or social change; representing or supporting an extreme or progressive section of a political party:

a radical activist.

▪ British English historical belonging to an extreme section of the Liberal party during the 19th century.

▪ characterized by independence of or departure from tradition; innovative or unorthodox:

the daring, avant-garde spirit of the music was too radical for the conservative audience.

3 Linguistics denoting or relating to the roots of a word.

▪ Music belonging to the root of a chord.

4 Mathematics relating to or forming the root of a number or quantity.

5 Botany of, or springing direct from, the root or stem base of a plant.

6 [usually as exclamation] North American English informal very good; excellent:

Okay, then. Seven o'clock. Radical!.

▸ noun

1 a person who advocates thorough or complete political or social change, or a member of a political party or section of a party pursuing such aims.

2 Chemistry a group of atoms behaving as a unit in a number of compounds. See also free radical

3 the root or base form of a word.

▪ any of the basic set of approximately 214 Chinese characters constituting semantically or functionally significant elements in the composition of other characters and used as a means of classifying characters in dictionaries.

4 Mathematics a quantity forming or expressed as the root of another.

▪ a radical sign.

– DERIVATIVES

radicalness noun

– ORIGIN late Middle English (in the senses ‘forming the root’ and ‘inherent’): from late Latin radicalis, from Latin radix, radic- ‘root’.